Natrijev Metamizolat Kalceks (Metamizole Sodium Monohydrate)

Metamizole sodium is indicated for conditions that require strong analgesic or antipyretic therapy within the pyrazolone class.

• Severe acute pain: provides rapid relief when conventional analgesics are inadequate.
• Post‑operative pain: helps control pain after surgical procedures.
• High fever: reduces elevated body temperature when other antipyretics are ineffective.

• Metamizole sodium inhibits cyclooxygenase activity, leading to reduced prostaglandin synthesis, which diminishes pain signaling and fever generation. While the exact pathway is not fully defined, the drug’s effect on prostaglandin-mediated processes underlies its analgesic and antipyretic properties.

Metamizole sodium may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Injection site pain: localized discomfort at the administration site.
• Nausea: mild to moderate upset stomach.
• Dizziness: transient light‑headedness.
• Skin rash: mild erythema or itching.
• Mild leukopenia: slight reduction in white blood cells.
• Transient hypotension: temporary drop in blood pressure.

Serious or Rare Side Effects

• Agranulocytosis: severe depletion of neutrophils, potentially life‑threatening.
• Anaphylaxis: acute, severe allergic reaction.
• Stevens‑Johnson syndrome: serious skin and mucous membrane disorder.
• Severe hypotension: marked blood pressure fall requiring intervention.
• Hepatic enzyme elevation: significant liver function changes.
• Blood dyscrasias: rare disorders of blood cell formation.

Metamizole sodium should be used with careful clinical oversight.

• Assess renal and hepatic function: adjust use if impairment is present.
• Monitor complete blood count: detect early signs of agranulocytosis.
• Avoid in patients with known hypersensitivity to pyrazolones.
• Do not use in individuals with a history of severe blood dyscrasias.
• Administer only under medical supervision: ensure appropriate dosing and monitoring.
• Store at ambient temperature: keep in the original pack, protect from moisture and direct sunlight.

Metamizole sodium can interact with several drug classes; awareness helps prevent adverse outcomes.

Major Interactions (Avoid)

• Concurrent myelosuppressive agents: increase risk of severe neutropenia.
• Other NSAIDs or pyrazolones: heighten potential for blood dyscrasias.
• Anticoagulants: may amplify bleeding tendency.

Moderate Interactions (Monitor Closely)

• Diuretics: may affect renal clearance, requiring dose adjustment.
• Antihypertensives: additive hypotensive effect.
• Opioid analgesics: possible enhanced sedation or respiratory depression.
• CYP450 modulators: may alter plasma levels, necessitating monitoring.